Transmitting Device, Receiving Device, Controlling Node, and Methods Therein, for Transmitting a Block to the Receiving Device

ABSTRACT

Embodiments include methods performed by a receiving device configured for operation in a communications network. The methods include receiving, from a transmitting device in the network, four bursts comprising a block mapped according to a selected block format, wherein the block comprises a plurality of data and header bits. In some embodiments, the block further comprises Stealing Flag bits and Uplink State Flag bits. The methods also include determining whether the selected block format corresponds to a first block format in which the plurality of data and header bits are repeated in a corresponding plurality of same first positions in all four bursts. The methods also include demodulating the plurality data and header bits based on the determination of whether the selected block format corresponds to the first block format. Embodiments also include receiving devices comprising a receiver and a processor configured to perform operations corresponding to the exemplary methods.

RELATED APPLICATIONS

This application is a Continuation of U.S. application Ser. No.15/950,272 filed Apr. 11, 2018, which is a Continuation of U.S.application Ser. No. 15/587,031 filed May 4, 2017, which is aContinuation of U.S. application Ser. No. 14/910,951 filed Feb. 8, 2016,which is a U.S. national-phase entry of International Appl.PCT/SE2015/051362 filed Dec. 17, 2015, which claims priority to U.S.Provisional Appl. No. 62/108,109 filed Jan. 27, 2015.

TECHNICAL FIELD

The present disclosure relates generally to a transmitting device andmethods performed thereby for transmitting a block to a receivingdevice. The present disclosure also relates generally to a receivingdevice and methods performed thereby for receiving the transmitted blockfrom the transmitting device. The present disclosure further relatesgenerally to a controlling node for selecting a block format fortransmission by the transmitting device to the receiving device. Thepresent disclosure additionally relates generally to computer programsand computer-readable storage mediums, having stored thereon thecomputer programs to carry out these methods.

BACKGROUND

Communication devices such as wireless devices are also known as e.g.User Equipments (UE), mobile terminals, wireless terminals and/or MobileStations (MS). Wireless devices are enabled to communicate wirelessly ina cellular communications network or wireless communication network,sometimes also referred to as a cellular radio system, cellular system,or cellular network. The communication may be performed e.g. between twowireless devices, between a wireless device and a regular telephoneand/or between a wireless device and a server via a Radio Access Network(RAN) and possibly one or more core networks, comprised within thewireless communications network.

Wireless devices may further be referred to as mobile telephones,cellular telephones, laptops, or surf plates with wireless capability,just to mention some further examples. The terminals in the presentcontext may be, for example, portable, pocket-storable, hand-held,computer-comprised, or vehicle-mounted mobile devices, enabled tocommunicate voice and/or data, via the RAN, with another entity, such asanother terminal or a server.

The wireless communications network covers a geographical area which isdivided into cell areas, wherein each cell area may be served by anaccess node such as a base station, e.g. a Radio Base Station (RBS),which sometimes may be referred to as e.g. “eNB”, “eNodeB”, “NodeB”, “Bnode”, or BTS (Base Transceiver Station), depending on the technologyand terminology used. The base stations may be of different classes suchas e.g. macro eNodeB, home eNodeB or pico base station, based ontransmission power and thereby also cell size. A cell is thegeographical area where radio coverage is provided by the base stationat a base station site. One base station, situated on the base stationsite, may serve one or several cells. Further, each base station maysupport one or several communication technologies. The base stationscommunicate over the air interface operating on radio frequencies withthe terminals within range of the base stations. In the context of thisdisclosure, the expression Downlink (DL) is used for the transmissionpath from the base station to the mobile station. The expression Uplink(UL) is used for the transmission path in the opposite direction i.e.from the mobile station to the base station.

Extended Coverage

Cellular systems continuously improve the network performance byintroducing new features and functionality. In GP-140421, “New SI onCellular System Support for Ultra Low Complexity and Low ThroughputInternet of Things”, GERAN#62, Vodafone, a new Study Item within 3rdGeneration Partnership Project (3GPP) was started that aims, amongstother things, to improve the DL and UL radio coverage of General PacketRadio Service (GPRS)/Enhanced GPRS (EGPRS) by up to 20 dB. A way toenhance coverage may be to use blind transmissions of the same radioblock with both the transmitter and receiver, being aware of how manyrepetitions may be used and how those repetitions may be transmitted inthe overall frame structure. A radio block, which may be referred toherein also as a “block”, may be understood as a well confined structurefor data and control message transfer that may be distributed over oneor more physical resources, referred to as “bursts”. Herein, a “block”may also refer to a structure for transfer of synchronization signalsand information. A “burst” may be understood as a well-defined physicalresource onto which the fields of the block are mapped. Blindtransmissions may be understood as a predetermined number oftransmissions to support extended coverage. The transmissions may besent blindly, that is, without feedback from the receiving end. Tomaximize the processing gain at the receiver, phase coherency at thetransmitter, between repetitions, may be required.

Current Block Format

A block may be comprised of bits. A bit may be understood as thesmallest unit of information in a digital information system. A bit ismost commonly represented as either a 0 or a 1. The bits comprising theblock may comprise information of different types. The types ofinformation may comprise: training sequence, stealing flags, data andheader and uplink state flag or USF. The types of information may beorganized in a particular manner. The manner in which the differenttypes of information are organized is known as the format of the block,or block format. The types of information may be understood to beorganized in fields. A field may be understood as a group of bits in amessage carrying a type of information. A field may be comprised of acontiguous or non-contiguous group, or groups of bits when mapped ontothe physical resource, that is, the burst(s).

The block format used for PACCH and PDTCH today in GSM may be dividedinto Stealing Flags (SFs), Uplink State Flags (USFs) and remainder ofthe block. The remainder of the block may be different depending onwhether the block is a PACCH block or a PDTCH block, but may consisttypically of a header and a data part, e.g., RLC/MAC header and RLC orcontrol data, and its bit-specific content differs from burst to burst.Since a radio block may be divided into 4 bursts the overallinterleaving depth, which may be understood herein as the range overwhich an information field is distributed, of the data and header partis four bursts.

A USF may be understood as an identifier in an UL scheduling mechanism.The identifier may schedule a certain MS in a next UL radio blockperiod. Among all MSs monitoring a DL radio block, only the single MSassigned the USF signaled in the DL radio block may be allowed totransmit in the next UL radio block period. For GMSK modulation, whichis the modulation scheme used by GPRS devices, the USF bits may bemapped onto different bit positions in the four different bursts of ablock, as shown in Table 1.

TABLE 1 GMSK USF bit mapping USF bit Burst position 0 0, 51, 102 1 100,35, 86 2 84, 19, 70 3 68, 3, 52

A Stealing Flag may be understood as a signal for the type of radioblock transmitted. The SF bits may be mapped onto the same bit positionsin each burst, namely the two bit positions on either side of thetraining sequence. A training sequence may be understood as predefinedsequence know by both transmitter and received, whose purpose may beunderstood as e.g. to facilitate estimation of the radio channel overwhich a burst may be transmitted.

The different fields of the current block format, also referred toherein as the legacy block format, are shown in FIG. 1, which is aschematic illustration of the current or existing block format. In theFigure, each burst is represented by a different row of bits. The toprow 200 represents the burst number 0, the second row 201 represents theburst number 1, the third row 202 represents the burst number 2, and thefourth row 203 represents the burst number 3. A bit is represented inthe Figure by a vertical rectangle. An individual bit 210 is marked. Thetype of information carried by each bit is illustrated with differentpatterns, as shown in the legend of the Figure. 58 bits are on each sideof the training sequence bits, which are flanked by the SF bits. The USFbits are located in the bit positions listed in Table 1. The remainingbits correspond to data and header type of information. All the bits inany single burst of the bursts 200, 201, 202, 203 comprising theTraining Sequence are referred to herein as the Training Sequence field220. All the bits in the block comprising the SF are referred to hereinas the SF field 230. All the bits in the block comprising data arereferred to herein as the data field. All the bits in the blockcomprising the header are referred to herein as the header field. Thedata and header fields may be referred to herein together as the dataand header fields 240, as shown in FIG. 1. All the bits in the blockcomprising the USF are referred to herein as the USF field 250.

Radio transmissions may be exposed to various impairments. One suchimpairment is the so-called frequency offset. A frequency offset may beunderstood as an offset between the frequency used by the transmitterand the receiver. A receiving device of a radio transmission may try tocompensate for such frequency offset by detecting the offset andcompensate for the same.

Blind transmissions of the same radio block have been suggested as a wayto enhance radio coverage in existing systems because these ifcoherently combined in, they may improve the signal to noise ratio,e.g., with up to 3 dB per doubling of repetitions, and thereby increasethe likelihood of correctly decoding a message. However, if such afrequency offset is not correctly estimated by the receiving device withexisting methods, this may destroy the coherency and degrade thereceiver processing gain when combining the repetitions. The processinggain in this context may be understood as the coverage performanceimprovement achieved by receiver algorithms. As a consequence thereceiving device may not be reached in the extended coverage scenario,as an extension of the coverage may not be achieved.

When using multiple blind transmissions, a.k.a., blind physical layertransmissions or just blind transmissions, the receiver, such as areceiving device, may typically combine and accumulate several of thesetransmissions before calling the demodulator, and hence before itattempts to demodulate and decode the block. In this accumulation ofmultiple transmissions, there may be a need to do the accumulation in aparticular way, so called coherently, in order not maximize theprocessing gain from these transmissions. In this process, a too highfrequency offset in the reception may be detrimental to the overallperformance. This is because a frequency offset leads to a phase driftover time which negatively impacts the possibility to combine thesamples from repeated bursts in order to achieve a desired processinggain. Hence, there may be, typically, an attempt from the receiver tocompensate for any frequency offset between transmissions that mayresult in a phase shift over time in the baseband representation of thesignal.

To address this, an excessive number of repetitions may be needed, whichresults in a poor utilization of available radio resources. Furthermore,with an improper estimation of the frequency offset in the reception,the same frequency offset may apply when the receiver is transmitting inthe opposite direction. Hence, an improper estimation in one directionmay impact performance in both UL and DL. Therefore, existing methodsfor extended coverage result in poor performance of the wirelesscommunications network.

Backwards Compatibility

Improper estimation of the frequency offset is not the only problemassociated with the introduction of devices supporting extended coveragein a network. When introducing new features into a network, it may oftenbe necessary to follow the requirement of backwards compatibility, i.e.,that the previous network operation may not be impacted negatively bythe introduction of the new feature.

This is because while the set of radio resources in the network may staythe same, devices of e.g., different capabilities depending on whetherthey support or not the new feature, may need to be allocated orscheduled on a common set of radio resources. That is, they may need tobe multiplexed, or scheduled at different time instances, on the sametime slot, or set of time slots.

In the particular case of Global System for Mobile Telephony(GSM)/General Packet Radio Service (GPRS) networks, for example, whenintroducing Enhanced General Packet Radio Service (EGPRS), providing aslittle impact as possible on the GPRS traffic was an important factor totake into account. One specific aspect that needed attention was thepossible multiplexing of legacy GPRS devices and EGPRS devices onto thesame physical resources, and that monitoring by legacy devices of the DLchannel to see if they are scheduled in the UL, by the reading of theUplink State Flag (USF) flag, was impacted to the least extent possible.As stated earlier, the USF signaled in the DL radio block may identifythe single MS assigned to it that may be allowed to transmit in the nextUL radio block period.

During a temporary block flow or TBF, a connection established between aMS and a BS to enable packet exchanges between them in GPRS networks,the USF may be carried by two different channels, the Packet DataTraffic Channel (PDTCH), which may carry user data, and the PacketAssociated Control Channel (PACCH), which may carry control signalingthat may be needed to support the user data flow.

The problem of backwards compatibility is not new to GSM/EDGE. Whenintroducing EGPRS, only partial multiplexing between GPRS and EGPRSdevices was achieved. This means that both GPRS and EGPRS devices may beassigned the same resources in the network. However, both DL and ULscheduling of GPRS devices using 8-ary Phase Shift Keying (8PSK)modulation, the new modulation scheme introduced with EGPRS, is notpossible, because the GPRS devices may only support Gaussian MinimumShift Keying (GMSK) modulation. Still, the block format for EGPRS whenusing GMSK modulation was done to ensure that GPRS mobiles could readit.

This was specifically achieved by the BTS coding the Stealing Flags (SF)for PDTCH indicating CS-4 from GPRS. A GPRS device may therefore be ableto interpret the SF as well as read the USF transmitted of EGPRS blockstransmitted with GMSK modulation. This is reflected in 3GPP TS 45.003v12.0.0, “Channel coding”, for the coding description of MCS-1, whichalso applies to MCS-2, -3 and -4, where it may be noted that:

“Note: For a standard GPRS MS, bits q(0), . . . , q(7) indicates thatthe USF is coded as for CS-4.”

q(0), . . . , q(7) is here referring to the Stealing Flag bits.

According to the foregoing, lack of backwards compatibility withexisting networks when introducing the extended coverage feature into anetwork may negatively impact the performance of the network due tounnecessary restrictions being imposed on to the network resourceallocation and scheduling method, as e.g., multiplexing of devicessupporting and not supporting extended coverage may not be possible.

Moreover, the frequency error offset associated with the blindrepetitions used to extend the coverage in a network may result afailure to reach the devices that are aimed to be reached, hencedegrading the performance of the network.

SUMMARY

It is therefore an object of embodiments herein to improve theperformance of a communications network by providing improved methods oftransmitting information to a receiving device. It is a particularobject of embodiments herein to improve the performance of acommunications network by providing improved methods of transmittinginformation to a receiving device in an extended coverage scenario.

According to a first aspect of embodiments herein, the object isachieved by a method performed by a transmitting device. The method isfor transmitting a block to a receiving device. The transmitting deviceand the receiving device operate in a wireless communications network.The transmitting device transmits a block to the receiving device. Theblock comprises four bursts. The four bursts further comprise UplinkState Flag (USF), Stealing Flag (SF), and data and header fields,wherein the USF and the SF fields are interleaved and mapped over thefour bursts. The data and header fields are interleaved over one burstbut repeated over the four bursts. The data and header fields areoverlapping with and overridden by bits from the USF field in differentpositions in each burst.

According to a second aspect of embodiments herein, the object isachieved by a method performed by the receiving device. The method isfor receiving the transmitted block from the transmitting device. Thetransmitting device and the receiving device operate in the wirelesscommunications network. The receiving device receives a block from thetransmitting device. The block comprises four bursts. The four burstsfurther comprise USF, SF and data and header fields. The USF and the SFfields are interleaved and mapped over the four bursts. The data andheader fields are interleaved over one burst but repeated over the fourbursts. The data and header fields are overlapping with and overriddenby bits from the USF field in different positions in each burst.

According to a third aspect of embodiments herein, the object isachieved by a method performed by a controlling node. The method is forselecting the block format for transmission by the transmitting deviceto the receiving device. The controlling node, the transmitting device,and the receiving device operate in the wireless communications network.The controlling node selects a block format for transmission by thetransmitting device to the receiving device. The block format comprisesfour bursts. The four bursts further comprise USF, SF and data andheader fields. The USF and the SF fields are interleaved and mapped overthe four bursts. The data and header fields are interleaved over oneburst but repeated over the four bursts. The data and header fields areoverlapping with and overridden by bits from the USF field in differentpositions in each burst. The controlling node sends, to the transmittingdevice, an indication for the selected block format.

According to a fourth aspect of embodiments herein, the object isachieved by the transmitting device configured to transmit the block tothe receiving device. The transmitting device and the receiving deviceare configured to operate in the wireless communications network. Thetransmitting device is further configured to transmit the block to thereceiving device. The block comprises four bursts. The four burstsfurther comprise USF, SF and data and header fields. The USF and the SFfields are interleaved and mapped over the four bursts. The data andheader fields are interleaved over one burst but repeated over the fourbursts. The data and header fields are overlapping with and overriddenby bits from the USF field in different positions in each burst.

According to a fifth aspect of embodiments herein, the object isachieved by the receiving device configured to receive the transmittedblock from the transmitting device. The transmitting device and thereceiving device are configured to operate in the wirelesscommunications network. The receiving device is further configured toreceive the block from the transmitting device. The block comprises fourbursts. The four bursts further comprise USF, SF and data and headerfields. The USF and the SF fields are interleaved and mapped over thefour bursts. The data and header fields are interleaved over one burstbut repeated over the four bursts. The data and header fields areoverlapping with and overridden by bits from the USF field in differentpositions in each burst.

According to a sixth aspect of embodiments herein, the object isachieved by a controlling node configured to select the block format fortransmission by the transmitting device to the receiving device. Thecontrolling node, the transmitting device, and the receiving device areconfigured to operate in the wireless communications network. Thecontrolling node is further configured to select the block format fortransmission by the transmitting device to the receiving device. Theblock format comprises four bursts. The four bursts further compriseUSF, SF and data and header fields. The USF and the SF fields areinterleaved and mapped over the four bursts. The data and header fieldsare interleaved over one burst but repeated over the four bursts. Thedata and header fields are overlapping with and overridden by bits fromthe USF field in different positions in each burst. The controlling nodesends, to the transmitting device 101, an indication for the selectedblock format.

According to a seventh aspect of embodiments herein, the object isachieved by a computer program, comprising instructions which, whenexecuted on at least one processor, cause the at least one processor tocarry out the method performed by the transmitting device.

According to an eighth aspect of embodiments herein, the object isachieved by a computer-readable storage medium, having stored thereonthe computer program, comprising instructions which, when executed on atleast one processor, cause the at least one processor to carry out themethod performed by the transmitting device.

According to a ninth aspect of embodiments herein, the object isachieved by a computer program, comprising instructions which, whenexecuted on at least one processor, cause the at least one processor tocarry out the method performed by the receiving device.

According to a tenth aspect of embodiments herein, the object isachieved by a computer-readable storage medium, having stored thereonthe computer program, comprising instructions which, when executed on atleast one processor, cause the at least one processor to carry out themethod performed by the receiving device.

According to an eleventh aspect of embodiments herein, the object isachieved by a computer program, comprising instructions which, whenexecuted on at least one processor, cause the at least one processor tocarry out the method performed by the controlling node.

According to a twelfth aspect of embodiments herein, the object isachieved by a computer-readable storage medium, having stored thereonthe computer program, comprising instructions which, when executed on atleast one processor, cause the at least one processor to carry out themethod performed by the controlling node.

By the transmitting device transmitting the block to the receivingdevice with the described format, that is, the block comprising fourbursts, the four bursts further comprising USF, SF and data and headerfields, wherein the USF and the SF fields are interleaved and mappedover the four bursts, wherein the data and header fields are interleavedover one burst but repeated over the four bursts, and wherein the dataand header fields are overlapping with and overridden by bits from theUSF field in different positions in each burst, effective frequencyoffset estimation is allowed. This in turn may help to optimize theperformance in extended coverage and help in followingtransmissions/receptions by having a low frequency offset. Moreover,backwards compatibility with legacy devices multiplexed on the sameresources may be maintained.

BRIEF DESCRIPTION OF THE DRAWINGS

Examples of embodiments herein are described in more detail withreference to the accompanying drawings, in which:

FIG. 1 is a schematic illustration of the current block format.

FIG. 2 is a schematic diagram illustrating frequency offset drift withinitial and continuous compensation.

FIG. 3 is a schematic diagram illustrating an example of a wirelesscommunications network, according to some embodiments.

FIG. 4 is a schematic illustration of the data and header part of thecurrent block format.

FIG. 5 is a schematic illustration of an example of the new blockformat, according to some embodiments.

FIG. 6 is a schematic illustration of the new block format, according tosome embodiments.

FIG. 7 is a schematic graph illustrating the impact on link levelperformance of data and header by overriding USF bits.

FIG. 8 is a schematic diagram illustrating embodiments of a method in atransmitting device, according to some embodiments.

FIG. 9 is a schematic diagram illustrating actions of a method in areceiving device, according to some embodiments.

FIG. 10 is a schematic diagram illustrating actions of a method in acontrolling node, according to some embodiments.

FIG. 11 is a block diagram of a transmitting device that is configuredaccording to some embodiments.

FIG. 12 is a block diagram of a receiving device that is configuredaccording to some embodiments.

FIG. 13 is a block diagram of a controlling node that is configuredaccording to some embodiments.

DETAILED DESCRIPTION Terminologies

The following commonly terminologies are used in the embodiments and areelaborated below:

Radio network node: In some embodiments the non-limiting term radionetwork node is more commonly used and it refers to any type of networknode serving a wireless device and/or connected to other network node ornetwork element or any radio node from where a wireless device receivessignal. Examples of radio network nodes are base transceiver station(BTS), Node B, base station (BS), multi-standard radio (MSR) radio nodesuch as MSR BS, eNode B, network controller, radio network controller(RNC), base station controller, relay, donor node controlling relay,Access Point (AP), transmission points, transmission nodes, RRU, RRH,nodes in distributed antenna system (DAS) etc.

Network node: In some embodiments a more general term “network node” isused and it may correspond to any type of radio network node or anynetwork node, which communicates with at least a radio network node.Examples of network node are any radio network node stated above, corenetwork node (e.g. MSC, MME etc.), O&M, OSS, SON, positioning node (e.g.E-SMLC), MDT etc.

Wireless device: In some embodiments the non-limiting term wirelessdevice is used and it refers to any type of wireless devicecommunicating with a radio network node in a cellular or mobilecommunication system. Examples of wireless device are target device,device to device mobile stations, machine type mobile stations or mobilestations capable of machine to machine communication, PDAs, iPAD,Tablet, mobile terminals, smart phone, laptop embedded equipped (LEE),laptop mounted equipment (LME), USB dongles etc.

Note that although terminology from the 3rd Generation PartnershipProject (3GPP) GERAN has been used in this disclosure to exemplify theembodiments herein, this should not be seen as limiting the scope of theembodiments herein to only the aforementioned system. Other wirelesssystems, including WCDMA, WiMax, and UMB may also benefit fromexploiting the ideas covered within this disclosure.

As part of the development of embodiments herein, a problem will firstbe identified and discussed.

As mentioned earlier, blind transmission of the same radio block havebeen suggested as a way to enhance radio coverage in existing systems.However, for optimal performance using blind transmissions a properestimation of the frequency offset at the receiver may be necessary. Inorder to efficiently estimate the frequency offset, and compensate forit at a low Signal-to-Noise Ratio (SNR), which may be the case whenoperating in extended coverage, a commonly used estimator may be basedon the knowledge that two or more identical signals have beentransmitted with a known separation in time. If it is assumed that twoof those are for example designated as s1 and s2, the frequency offsetmay be estimated by taking sum(s1*s2′), where the ‘-operator is thecomplex conjugate of the signal. The resulting complex vector may have aphase, which is an estimation of the phase drift between s1 and s2, andhence, by knowing the time separation between the two transmissions, thephase drift over time, and hence the frequency offset may be estimated,by e.g., the receiving device.

However, with a large enough separation in time, e.g., T, the estimationof frequency offset may not be done in an unambiguous way due to the 2πperiodicity of the phase. A detected phase θ at time T may be a resultof a range of frequency offset (θ±2πN)/T radians, where N is anarbitrary integer.

A correct estimation of the frequency offset may not only be importantfor the receiver side in a device, but also for the transmitter side ofthe device so that it may correct its own frequency drift continuously.

A typical data transmission by a device such as a MS may be take placein the following manner:

-   -   1. The device may synchronize to a cell and correct its        frequency from the synchronization channel(s);    -   2. The device may read system information on a broadcast channel        to determine, among other things, that it is allowed to access        the network and what transmit power to use;    -   3. The device may send a Random Access to the network, that is,        a network node, to ask for resources;    -   4. The network may assign resources to the device by a control        block on the DL;    -   5. The device may transmit on the resources and wait for a        control message on the DL to know the status of the        transmission;    -   6. Step 3, 4 is may be repeated until the data transmission is        finished.

With the described procedure, the frequency drift may only be correctedat the synchronization to the cell, and possibly during the systeminformation acquisition, but may then drift during the data transfer.FIG. 2 is a schematic diagram illustrating a frequency offset drift withinitial compensation in the top graph, according to existing methods. Inthe top graph only step 1 above is executed, so the frequency estimationand correction is only accomplished during the initial step 1 justdescribed. As may be appreciated in the top graph in the Figure, therate of the phase drift is increasing with time, as shown by thepositive slope, which implies a larger frequency offset. However, if thecontrol block, that is the block in e.g., the PACCH, on the DL isdesigned for effective frequency offset estimate, so the device maycompensate for it, the drift may only occur during a short period, andhence be compensated for with the receipt of every DL control messagetransmission, as shown by the bottom graph in FIG. 2. The bottom graphin FIG. 2 illustrates frequency offset drift with continuouscompensation. As in the top graph of the Figure, the rate of the phasedrift is increasing with time, as shown by the positive slope. In thebottom graph, the frequency offset may be corrected by the receiverevery time a control block, e.g., a PACCH, is received per step 5 above.In the bottom graph, when the frequency offset is compensated, thefrequency offset is lowered or completely removed, which is showed as adiscontinuation of the curve. When the device starts to transmit afterthe frequency offset compensation, the drift is increased again, shownby the positive slope, but does not reach values as high as the casewithout frequency offset compensation, as shown in the top part ofFigure.

In conclusion, from FIG. 2 it may be understood that using a simpleapproach by just repeating the current control block on the DL by blindrepetition may imply that the same bursts blindly repeated may beseparated by a distance too far in time, for the receiver tounambiguously and effectively determine the frequency offset. Ensuring asmaller spacing in time may ease the frequency offset estimation, andalso the range of frequency offsets possible to detect.

Embodiments herein will now be described, which address theaforementioned issues by providing methods that allow for effectivefrequency offset estimation in extended coverage. In this section, theembodiments herein will be illustrated in more detail by a number ofexemplary embodiments. It should be noted that these embodiments are notmutually exclusive. Components from one embodiment may be tacitlyassumed to be present in another embodiment and it will be obvious to aperson skilled in the art how those components may be used in the otherexemplary embodiments. Several embodiments are comprised herein. Morespecifically, the following are transmitting device related embodiments,receiving device related embodiments, and controlling node relatedembodiments.

FIG. 3 depicts an example of a wireless communications network 100,sometimes also referred to as a cellular radio system, cellular networkor wireless communications system, in which embodiments herein may beimplemented. The wireless communications network 100 may for example bea network such as a Global System for Mobile communications (GSM)network, GSM/Enhanced Data Rate for GSM Evolution (EDGE) Radio AccessNetwork (GERAN) network, EDGE network or a network comprising of acombination of Radio Access Technologies (RATs) such as e.g.Multi-Standard Radio (MSR) base stations, where GSM/EDGE is included asone of the RATs supported. Thus, although terminology from 3GPP GERANmay be used in this disclosure to exemplify embodiments herein, thisshould not be seen as limiting the scope of the embodiments herein toonly the aforementioned system.

The wireless communications network 100 comprises a transmitting device101 and a receiving device 102. The transmitting device 101 may be aradio network node, such as a network node 110 described below, or awireless device such as a wireless device 120 described below. Thereceiving device 102 may be a radio network node, such as a network node110 described below, or a wireless device such as a wireless device 120described below. In the non-limiting particular example illustrated inFIG. 3, the transmitting device 101 is the network node 110, and thereceiving device is the wireless device 120.

The wireless communications network 100 comprises a plurality of networknodes whereof the network node 110 is depicted in FIG. 3. The networknode 110 may be, for example, a base station such as e.g., a BaseTransceiver Station (BTS), femto Base Station, MSR BS, micro BTS, picoBTS, or any other network unit capable to serve a device or a machinetype communication device in a wireless communications network 100. Insome particular embodiments, the network node 110 may be a stationaryrelay node or a mobile relay node. The wireless communications network100 covers a geographical area which is divided into cell areas, whereineach cell area is served by a network node, although, one network nodemay serve one or several cells. In the examples depicted in FIG. 3, thenetwork node 110 serves a cell 130. The network node 110 may be ofdifferent classes, such as e.g. macro, micro or pico base station, basedon transmission power and thereby also cell size. Typically, wirelesscommunications network 100 may comprise more cells similar to cell 130,served by their respective network nodes. This is not depicted in FIG. 3for the sake of simplicity. The network node 110 may support one orseveral communication technologies, and its name may depend on thetechnology and terminology used. In 3GPP GERAN, network nodes such asthe network node 110, which may be referred to as BTS or Radio BaseStation (RBS), may be directly connected to one or more networks, e.g.,core networks or the internet, which are not illustrated in FIG. 32. Thenetwork node 110 may be any of the nodes in these one or more networks.For example, in GSM, the network node 110 may be connected to acontrolling node 140, such as a Base Station Controller (BSC) 140. Thenetwork node 110 may communicate with the controlling node 140, e.g.,the BSC 140, over a link 150.

A number of wireless devices are located in the wireless communicationsnetwork 100. In the example scenario of FIG. 3, only one mobile stationis shown, wireless device 120. Any reference to a “user node” “mobilestation” or “MS” herein is meant to comprise a reference to the wirelessdevice 120, indistinctively, unless noted otherwise. The wireless device120 may communicate with the network node 110 over a radio link 160.

The wireless device 120 is a wireless communication device such as amobile station which is also known as e.g. mobile terminal, wirelessterminal and/or UE. The device is wireless, i.e., it is enabled tocommunicate wirelessly in the wireless communication network 100,sometimes also referred to as a cellular radio system or cellularnetwork. The communication may be performed e.g., between two devices,between a device and a regular telephone and/or between a device and aserver. The communication may be performed e.g., via a RAN and possiblyone or more core networks, comprised within the wireless network.

The wireless device 120 may further be referred to as a mobiletelephone, cellular telephone, or laptop with wireless capability, justto mention some further examples. The wireless device 120 in the presentcontext may be, for example, portable, pocket-storable, hand-held,computer-comprised, or vehicle-mounted mobile devices, enabled tocommunicate voice and/or data, via the RAN, with another entity, such asa server, a laptop, a Personal Digital Assistant (PDA), or a tabletcomputer, sometimes referred to as a surf plate with wirelesscapability, Machine-to-Machine (M2M) devices, devices equipped with awireless interface, such as a printer or a file storage device or anyother radio network unit capable of communicating over a radio link in acellular communications system.

Embodiments herein may be understood to relate to providing an improvedblock format in extended coverage for effective frequency offsetestimation, while providing backwards compatibility. Particularembodiments herein may be understood to relate to a backwards compatibleand improved block format in extended coverage for GSM/Enhanced Datarates for GSM Evolution (EDGE).

New Block Format

In order to enable effective frequency offset estimation in a receivingdevice, while at the same time providing backwards compatibility, inextended coverage embodiments herein may provide a new block format. Thenew block format provided herein will be described first to help in theunderstanding of the actions of the methods described later in relationto FIGS. 8 and 9.

With regards to the current block format described in FIG. 1, if onlythe data and header part may be considered, the current block format maybe represented as in FIG. 4, which is a schematic illustration of thedata and header part of the current block format mapped onto the fourbursts. The manner in which the bits and bursts are represented is thesame as in FIG. 1. The legend of the Figure indicates the pattern chosento represent the bits of each one of the 4 bursts, burst 0, burst 1,burst 2 and burst 3. Hence, in the current block format represented inFIG. 4, the data and header part reside in unique bit positions in theoverall bursts, and the content may be different depending on the burstit is mapped to.

According to embodiments of the new block format herein, the bitscarrying encoded data/header may be mapped onto one burst that may berepeated over at least four consecutive bursts to allow efficientfrequency offset estimation, while the bits carrying USF and SF may bemapped over four consecutive bursts, as per legacy GPRS/EGPRS, to allowlegacy MS, that is, legacy receiving devices, to read them.

In order to enhance the coverage by repeating transmissions, in oneexample according to embodiments herein, the new block format maycontain the same information in all four bursts of the radio block apartfrom the Stealing Flags, which may be coded and mapped as today, in thecurrent block format. FIG. 5 is a schematic illustration of the data andheader part mapped onto the four bursts according to an example of thenew block format described herein. The manner in which the bits andbursts are represented is the same as in FIG. 1. The legend of theFigure indicates the pattern chosen to represent the bits carrying dataand header information in each one of the 4 bursts, burst 0, burst 1,burst 2 and burst 3, which as indicated in the legend, have now the samecontent. FIG. 5 shows only the data and header part of the block, but asmay be noted, the length per half burst may be 57, and hence the bitclosest to the training sequence may still be the Stealing Flag, as inthe current design, see FIG. 1. In the same example, USF bits overridethe bits in the positions where the USF bits currently map, see Table 1.This is shown in FIG. 6. By the fact the USF bits override the bits itis meant that the original bits may be overwritten by the USF bits.

FIG. 6 is a schematic illustration of the data and header part in anexample of the new block format described herein, mapped onto the fourbursts, with USF bits overriding, as indicated by the + sign, parts ofthe data and header bits, according to the new block format, describedherein. The manner in which the bits and bursts are represented is thesame as in FIG. 1. The legend of the Figure indicates the pattern chosento represent the bits carrying data and header information each one ofthe 4 bursts, burst 0, burst 1, burst 2 and burst 3, which as indicatedin the legend, have now the same content. In the lower half of theFigure, the USF bits are represented within empty blocks correspondingto the size of the data and header fields, to indicate the positions ofthe data and header bits overridden by bits from the USF field in thenew block format.

As may be seen in FIG. 6, and Table 1, there may be no overlap of any ofthe USF bit position between the bursts, i.e., for these 12 bitpositions, the accumulation of multiple transmissions may effectively bethree-quarter of useful signal and one-quarter of interfering USF bits.Considering that there could be, in total, 114 bits in the burst, 57+57,deducting the 8 bits from the Stealing Flags, the performance, is notexpected to be significantly impacted by overriding the USF bitpositions, which only constitute 12 out of the 114 bit positions in theburst, and for each of the 12 bit positions there will still bethree-quarter of useful signal (signal where USF has not beenoverridden) received.

This has in fact been evaluated by link level simulations, see FIG. 7. Alink level simulation may be understood as the radio link performance interms of BLock Error Rate (BLER) versus experienced Signal to NoiseRatio (SNR). It may be seen that the degradation, which may beunderstood as the increase needed in SNR to achieve a constant BLER, maybe limited to around 0.2 dB. FIG. 7 is a schematic graph illustratingthe impact on link level performance of data and header by overridingUSF bits. In FIG. 7, the x-axis shows the Signal-to-Noise ratio,measured as energy per bit to noise power spectral density ratio(Es/N0), in decibel, with the y-axis showing the BLock Error Rate (BLER)of the simulated block. Hence, if, for example, reading the figure atthe same block error rate for the two different curves, the necessaryincrease or decrease in SNR may be obtained to maintain performance. Inother words, overriding of the data bits with the USF bits does notnegatively impact the Signal-to-Noise ratio.

To avoid that a legacy EGPRS MS may try to decode a block of the newformat, which may be a waste of battery, the Stealing Flags may be setto a value indicating a Coding Scheme (CS) not used by EGPRS MS, i.e.,CS-2 or CS-3. GPRS MS may still try to decode the block but fail due tothe new format. Hence, battery in the legacy receiving devices may besaved by avoiding that they continue in trying to decode the blockaccording to embodiments herein.

The above mentioned block design is summarized in Table 2, which is asummary of an example of the new block format disclosed herein, incomparison with a legacy block format.

TABLE 2 Block field Legacy block format New block format USF Interleavedand mapped Interleaved and mapped over 4 over 4 bursts. Non- bursts (asper legacy mapping). overlapping with other Fully overlapping with dataand fields header part, with USF bits overriding the corresponding dataand/or header bits SF Interleaved and mapped Interleaved and mapped over4 over 4 bursts. Non- bursts (as per legacy mapping). overlapping withother Non-overlapping with other fields fields Data and Interleaved andmapped Interleaved over 1 burst but header over 4 bursts. Non- mapped(repeated) over 4 bursts. overlapping with other Overlapping andoverridden by fields USF bits in different positions in each burst.

It will be understood from Table 2, that in embodiments herein, each ofthe data field and the header field is interleaved over 1 burst butmapped, that is, repeated, over 4 bursts. Each of the data field and theheader field is overlapping and overridden by USF bits in differentpositions in each burst. This is in contrast with the legacy or currentblock format, wherein each of the data field and the header field isinterleaved and mapped over 4 bursts, and non-overlapping with otherfields. Overlapping may be understood herein to refer to as overwritingthe original data and header parts. The overlapping of the data andheader fields by the USF bits may be understood to be partial, as shownin FIG. 6.

The new block format may ensure that the same signal is repeated using atime separation of one quarter of the current block format. With thetime separation being one quarter of the current block format, themaximum frequency offset that may be estimated is four times higher thanfor the current block format. The maximum limit for frequency offsetestimation may be due to the periodicity of the phase, which may be usedto estimate the offset, i.e. ±2πN, where any value of integer N mayresult in the same phase shift.

Embodiments of a method performed by the transmitting device 101 fortransmitting the block according to embodiments herein to the receivingdevice 102, will now be described with reference to the flowchartdepicted in FIG. 8. As stated earlier, the transmitting device 101 andthe receiving device 102 operate in the wireless communications network100.

In some embodiments, the transmitting device 101 may be a BTS and thereceiving device 102 may be a mobile station.

In some embodiments, the transmitting device 101 may be a mobile stationand the receiving device 102 may be a BTS.

In some embodiments, the controlling node 140 may be a BSC.

Action 801

In this action, the transmitting device 101 may receive from thecontrolling node 140 operating in the wireless communications network100, an indication of a block format of a block for transmission to thereceiving device 102, e.g., from a plurality of block formats, the otherformats comprising for example, a legacy or current block format, asdescribed herein. The receiving may be via the link 150. Block formathas been described earlier. In Action 801, the block format may comprisethe new block format described in FIGS. 4 and 5. The block format mayhave been selected by the controlling node 140, as will be describedlater in Action 1001.

The indication may be for example in the form of a Stealing Flag (SF) inan RLC/MAC data block, such the EC-PDTCH in GSM.

As described in relation to FIGS. 4 and 5, the block comprises fourbursts. The four bursts further comprise USF, SF, and data and headerfields, as described earlier. The USF and the SF fields are interleavedand mapped over the four bursts, wherein the data and header fields areinterleaved over one burst but repeated over the four bursts. The dataand header fields are overlapping with and overridden by bits from theUSF field in different positions in each burst.

The fact that the data and header fields are repeated over the fourbursts may be understood as that, the bits carrying encoded data/headermay be mapped onto one burst that may be repeated over at least fourconsecutive bursts, as stated earlier.

In some embodiments, the block may be a block comprising controlinformation, such as positive and negative acknowledgments of receivedblocks. That, is the block format may be a control block format.

In some embodiments, the receiving 801 may further comprise receiving anindication for a selected state for the USF field in the selected blockformat. A state is understood herein as an identifier for a particulardevice to be scheduled on the UL. For example, in GSM, eight different“states” may be supported, wherein, one MS may be assigned one “state”,e.g., 000. The state may have been selected by e.g., the controllingnode 140, depending on which wireless device the controlling node 140may decide to schedule. The indication for the selected state for theUSF field may be understood as the identifier of a scheduled receivingdevice, such as the receiving device 102.

In some embodiments, the wireless communications network 100 may be anetwork that may need to be backwards compatible while supporting thenew block format for new devices, but still having an interest in thatthe new block format, or parts of it, may be read by legacy devices,e.g., the legacy devices may need to understand the training sequence tobe able to find the block and demodulate it, and then the SF and USFbits after demodulation may need to be compatible in the placement andtheir bit value for legacy devices to understand it.

In accordance with this, in some embodiments, the block may be backwardscompatible by the USF field being mapped over the four bursts, so thatthe receiving device 102, in embodiments lacking a specificconfiguration to support the block format, may be enabled to decode theUSF carried by the block.

New MSs, such as the receiving device 102 in some embodiments,compatible with the new block format may also use SF and USF bits to,with the SF, distinguish between different block formats, and for USF,determine if they are scheduled in the UL.

Action 801 is optional, as represented in FIG. 8 by the dashed lines,since in some embodiments it may be the transmitting device 101 itselfdeciding which block format the block to transmit to the receivingdevice 102 may have.

Action 802

According to this Action 802, the transmitting device 101 transmits theblock, as just described in Action 801, to the receiving device 102.Transmission may be performed e.g., via the radio link 160 by the PDTCHor the PACCH.

In short, embodiments herein may be understood as introducing a blockthat may be designed by using a single burst, instead of the currentdesign of four different bursts per block, in order to allow forextended coverage and at the same time, improved frequency offsetestimation.

In addition, in order to be backwards compatible with the existing blockdesign, the following principles may be followed:

First, the burst may be repeated at minimum four times, in order tooccupy the same amount of resources as the conventional block;

Second, the Stealing flags (SFs) may be spread out over all four bursts,and may be of different states depending on the bursts, out of the four,they are mapped to, to describe the type of radio block transmitted. TheSFs may be spread and coded in the same manner as the conventional blockto allow legacy devices to read and interpret the SFs.

Third, the USF bits may be spread out over all four bursts, and may beof different states depending on burst number. The USF bits may bespread and coded in the same manner as the conventional block—overridingbits from the data part of the 1-burst coded block—to allow legacydevices to read and interpret the USF.

Embodiments herein may be applicable to GSM. Although the overalldescription is provided for a control block format, the same principlesmay apply for other block formats, such as the one used on the packetdata traffic channel.

Embodiments herein may provide the following advantages:

-   -   First, they provide superior performance in extended coverage        due to the improved processing power when combining multiple        transmissions due to the improved frequency offset estimation        compared to a straight forward extension of current design;    -   Second, the design may allow for effective frequency offset        estimation, which may help to optimize the performance in        extended coverage and help in following transmissions/receptions        by having a low frequency offset. The effective frequency offset        estimation may be achieved by correlation.    -   Third, backwards compatibility with legacy devices multiplexed        on the same resources may be maintained, by the placement of the        SF and USF fields.

Embodiments of a method performed by the receiving device 102 forreceiving the transmitted block from the transmitting device 101, willnow be described with reference to the flowchart depicted in FIG. 9. Asstated earlier, the transmitting device 101 and the receiving device 102operate in the wireless communications network 100.

The detailed description of some of the following corresponds to thesame references provided above, in relation to the actions described forthe transmitting device 101, and will thus not be repeated here.

Action 901

In this action, the receiving device 102 receives the block from thetransmitting device 101. The block comprises the four bursts. The fourbursts further comprise USF, SF and data and header fields. The USF andthe SF fields are interleaved and mapped over the four bursts. The dataand header fields are interleaved over one burst but repeated over thefour bursts. The data and header fields are overlapping with andoverridden by bits from the USF field in different positions in eachburst. The receiving may be performed e.g., via the radio link 160, bythe PDTCH or the PACCH.

Action 902

In some embodiments, the receiving device 102 may decode the receivedblock according to an indication comprised in the SF field of thereceived block. That is, the receiving device 102 in embodiments whereinit may be compatible with the new block format, may also use the SF bitsto distinguish between different block formats. By knowing the blockformat of the block received in Action 901, the receiving device 102 maythen identify if the block was intended for it or not, and if intendedfor it, avoid multiple decoding attempts assuming different blockformats.

Additionally, the receiving device 102 may use the USF to determine ifit is scheduled in the UL.

In other embodiments, the receiving device 102 may lack a specificconfiguration to support the block format. That is, in some embodiments,the receiving device 102 may be a legacy device that may not beconfigured to operate with a system that is more advanced than aGSM/EDGE network, Release 12. In such embodiments, the block may bebackwards compatible by the USF field being mapped over the four burstsso that the receiving device 102 may be enabled to decode the USFcarried by the block.

Action 902 is optional, as represented in FIG. 9 by the dashed lines.

Embodiments of a method performed by the controlling node 140 forselecting the block format for transmission by the transmitting device101 to the receiving device 102, will now be described with reference tothe flowchart depicted in FIG. 10. As stated earlier, the controllingnode 140, the transmitting device 101, and the receiving device 102operate in the wireless communications network 100.

The detailed description of some of the following corresponds to thesame references provided above, in relation to the actions described forthe transmitting device 101, and will thus not be repeated here.

Action 1001

In this action, the controlling node 140 selects the block format, asdescribed in FIGS. 5 and 6, for transmission by the transmitting device101 to the receiving device 102. The block format comprises four bursts.The four bursts further comprise USF, SF, and data and header fields.The USF and the SF fields are interleaved and mapped over the fourbursts. The data and header fields are interleaved over one burst butrepeated over the four bursts. The data and header fields areoverlapping with and overridden by bits from the USF field in differentpositions in each burst.

The controlling node 140 may select the block format based on, forexample, if the receiving device 102 that is to be scheduled supportsthe block format.

Action 1002

In some embodiments, the controlling node 140 may select a state for theUSF field in the selected block, to determine which device may bescheduled in the UL.

The controlling node 140 may perform this action according to knownmethods.

Action 1002 is optional, as represented in FIG. 10 by the dashed lines.

Action 1003

In this Action, the controlling node 140 sends, to the transmittingdevice 101, the indication for the selected block format. This is doneso that the transmitting device 101 may know which block format to usefor transmission to the receiving device 102. The sending in this Actionmay be done via the link 150.

As mentioned earlier, in some embodiments, the block may be backwardscompatible by the USF field being mapped over the four bursts so thatthe receiving device 102 lacking a specific configuration to support theblock format, may be enabled to decode the USF carried by the block.

To perform the method actions described above in relation to FIG. 8, thetransmitting device 101 is configured to transmit the block to thereceiving device 102. The transmitting device 101 comprises thefollowing arrangement depicted in FIG. 11. As already mentioned, thetransmitting device 101 and the receiving device 102 are configured tooperate in the wireless communications network 100.

The detailed description of some of the following corresponds to thesame references provided above, in relation to the actions described forthe transmitting device 101, and will thus not be repeated here.

The transmitting device 101 is further configured to, e.g., by means ofa transmitting module 1101 configured to, transmit the block to thereceiving device 102, the block comprising four bursts, the four burstsfurther comprising USF, SF, and data and header fields, wherein the USFand the SF fields are interleaved and mapped over the four bursts,wherein the data and header fields are interleaved over one burst butrepeated over the four bursts, and wherein the data and header fieldsare overlapping with and overridden by bits from the USF field indifferent positions in each burst.

The transmitting module 1101 may be a processor 1104 of the transmittingdevice 101.

The transmitting device 101 may be further configured to, e.g., by meansof a receiving module 1102 configured to, receive from the controllingnode 140 configured to operate in the wireless communications network100, the indication of the block format of the block for transmission tothe receiving device 102. The block format may have been configured tohave been selected by the controlling node 140.

The receiving module 1102 may be the processor 1104 of the transmittingdevice 101.

In some embodiments, to receive may further comprise to receive theindication for the selected state for the USF field in the selectedblock format.

In some embodiments, the block may be configured to be backwardscompatible by the USF field being mapped over the four bursts so thatthe receiving device 102 lacking a specific configuration to support theblock format, may be enabled to decode the USF carried by the block.

The transmitting device 101 may be configured to perform other actionswith other modules 1103 configured to perform these actions within thetransmitting device 101. Each of the other modules 1103 may be theprocessor 1104 of the transmitting device 101, or an application runningon such processor.

The embodiments herein may be implemented through one or moreprocessors, such as a processor 1104 in the transmitting device 101depicted in FIG. 11, together with computer program code for performingthe functions and actions of the embodiments herein. The program codementioned above may also be provided as a computer program product, forinstance in the form of a data carrier carrying computer program codefor performing the embodiments herein when being loaded into the in thetransmitting device 101. One such carrier may be in the form of a CD ROMdisc. It is however feasible with other data carriers such as a memorystick. The computer program code may furthermore be provided as pureprogram code on a server and downloaded to the transmitting device 101.

The transmitting device 101 may further comprise a memory 1105comprising one or more memory units. The memory 1105 is arranged to beused to store obtained information, store data, configurations,schedulings, and applications etc. to perform the methods herein whenbeing executed in the transmitting device 101.

In some embodiments, the transmitting device 101 may receive informationthrough a receiving port 1106. In some embodiments, the receiving port1106 may be, for example, connected to two or more antennas intransmitting device 101. In other embodiments, the transmitting device101 may receive information from another structure in the wirelesscommunications network 100 through the receiving port 1106. Since thereceiving port 1106 may be in communication with the processor 1104, thereceiving port 1106 may then send the received information to theprocessor 1104. The receiving port 1106 may also be configured toreceive other information.

The processor 1104 in the transmitting device 101 may be furtherconfigured to transmit or send information to e.g., the receiving device102 or the controlling node 140, through a sending port 1107, which maybe in communication with the processor 1104 and the memory 1105.

Those skilled in the art will also appreciate that the transmittingmodule 1101, the receiving module 1102, and the other modules 1103described above may refer to a combination of analog and digitalmodules, and/or one or more processors configured with software and/orfirmware, e.g., stored in memory, that, when executed by the one or moreprocessors such as the processor 1104, perform as described above. Oneor more of these processors, as well as the other digital hardware, maybe included in a single Application-Specific Integrated Circuit (ASIC),or several processors and various digital hardware may be distributedamong several separate components, whether individually packaged orassembled into a System-on-a-Chip (SoC).

Also, in some embodiments, the different modules 1101-1103 describedabove may be implemented as one or more applications running on one ormore processors such as the processor 1104.

Thus, the methods according to the embodiments described herein for thetransmitting device 101 may be implemented by means of a computerprogram product, comprising instructions, i.e., software code portions,which, when executed on at least one processor, cause the at least oneprocessor to carry out the actions described herein, as performed by thetransmitting device 101. The computer program product may be stored on acomputer-readable storage medium. The computer-readable storage medium,having stored thereon the computer program, may comprise instructionswhich, when executed on at least one processor, cause the at least oneprocessor to carry out the actions described herein, as performed bytransmitting device 101. In some embodiments, the computer-readablestorage medium may be a non-transitory computer-readable storage medium,such as a CD ROM disc, or a memory stick. In other embodiments, thecomputer program product may be stored on a carrier containing thecomputer program just described, wherein the carrier is one of anelectronic signal, optical signal, radio signal, or thecomputer-readable storage medium, as described above.

To perform the method actions described above in relation to FIG. 9, thereceiving device 102 is configured to receive the transmitted block fromthe transmitting device 101. The receiving device 102 comprises thefollowing arrangement depicted in FIG. 12. As already mentioned, thetransmitting device 101 and the receiving device 102 are configured tooperate in the wireless communications network 100.

The detailed description of some of the following corresponds to thesame references provided above, in relation to the actions described forthe transmitting device 101, and will thus not be repeated here.

The first communication device 101 is further configured to, e.g., bymeans of a receiving module 1201 configured to, receive the block fromthe transmitting device 101, the block comprising four bursts, the fourbursts further comprising USF, SF and data and header fields, whereinthe USF and the SF fields are interleaved and mapped over the fourbursts, wherein the data and header fields are interleaved over oneburst but repeated over the four bursts, and wherein the data and headerfields are overlapping with and overridden by the USF fields bits fromthe USF field in different positions in each burst.

The receiving module 1201 may be a processor 1204 of the receivingdevice 102.

In some embodiments, the block may be configured to be backwardscompatible by the USF field being mapped over the four bursts so thatthe receiving device 102 lacking a specific configuration to support theblock format, may be enabled to decode the USF carried by the block.

The receiving device 102 may be further configured to, e.g., by means ofa decoding module 1202 configured to, decode the block according to theindication comprised in the SF field of the received block.

The decoding module 1202 may be the processor 1204 of the receivingdevice 102.

The receiving device 102 may be configured to perform other actions withother modules 1203 configured to perform these actions within thereceiving device 102. Each of the other modules 1203 may be theprocessor 1204 of the receiving device 102, or an application running onsuch processor.

The embodiments herein may be implemented through one or moreprocessors, such as a processor 1204 in the receiving device 102depicted in FIG. 12, together with computer program code for performingthe functions and actions of the embodiments herein. The program codementioned above may also be provided as a computer program product, forinstance in the form of a data carrier carrying computer program codefor performing the embodiments herein when being loaded into the in thereceiving device 102. One such carrier may be in the form of a CD ROMdisc. It is however feasible with other data carriers such as a memorystick. The computer program code may furthermore be provided as pureprogram code on a server and downloaded to the receiving device 102.

The receiving device 102 may further comprise a memory 1205 comprisingone or more memory units. The memory 1205 is arranged to be used tostore obtained information, store data, configurations, schedulings, andapplications etc. to perform the methods herein when being executed inthe receiving device 102.

In some embodiments, the receiving device 102 may receive informationthrough a receiving port 1206. In some embodiments, the receiving port1206 may be, for example, connected to two or more antennas in thereceiving device 102. In other embodiments, the receiving device 102 mayreceive information from another structure in the wirelesscommunications network 100 through the receiving port 1206. Since thereceiving port 1206 may be in communication with the processor 1204, thereceiving port 1206 may then send the received information to theprocessor 1204. The receiving port 1206 may also be configured toreceive other information.

The processor 1204 in the receiving device 102 may be further configuredto transmit or send information to e.g., the transmitting device 101,through a sending port 1207, which may be in communication with theprocessor 1204 and the memory 1205.

Those skilled in the art will also appreciate that the receiving module1201, the decoding module 1202, and the other modules 1203 describedabove may refer to a combination of analog and digital modules, and/orone or more processors configured with software and/or firmware, e.g.,stored in memory, that, when executed by the one or more processors suchas the processor 1204, perform as described above. One or more of theseprocessors, as well as the other digital hardware, may be included in asingle Application-Specific Integrated Circuit (ASIC), or severalprocessors and various digital hardware may be distributed among severalseparate components, whether individually packaged or assembled into aSystem-on-a-Chip (SoC).

Also, in some embodiments, the different modules 1201-1203 describedabove may be implemented as one or more applications running on one ormore processors such as the processor 1204.

Thus, the methods according to the embodiments described herein for thereceiving device 102 may be implemented by means of a computer programproduct, comprising instructions, i.e., software code portions, which,when executed on at least one processor, cause the at least oneprocessor to carry out the actions described herein, as performed by thereceiving device 102. The computer program product may be stored on acomputer-readable storage medium. The computer-readable storage medium,having stored thereon the computer program, may comprise instructionswhich, when executed on at least one processor, cause the at least oneprocessor to carry out the actions described herein, as performed byreceiving device 102. In some embodiments, the computer-readable storagemedium may be a non-transitory computer-readable storage medium, such asa CD ROM disc, or a memory stick. In other embodiments, the computerprogram product may be stored on a carrier containing the computerprogram just described, wherein the carrier is one of an electronicsignal, optical signal, radio signal, or the computer-readable storagemedium, as described above.

To perform the method actions described above in relation to FIG. 10,the controlling node 140 is configured to select the block format fortransmission by the transmitting device 101 to the receiving device 102.The controlling node 140 comprises the following arrangement depicted inFIG. 13. As already mentioned, the controlling node 140, thetransmitting device 101, and the receiving device 102 are configured tooperate in the wireless communications network 100.

The detailed description of some of the following corresponds to thesame references provided above, in relation to the actions described forthe controlling node 140, and will thus not be repeated here.

The controlling node 140 is further configured to, e.g., by means of aselecting module 1301 configured to, select the block format fortransmission by the transmitting device 101 to the receiving device 102,the block format comprising four bursts, the four bursts furthercomprising USF, SF and data and header fields, wherein the USF and theSF fields are interleaved and mapped over the four bursts, wherein thedata and header fields are interleaved over one burst but repeated overthe four bursts, and wherein the data and header fields are overlappingwith and overridden by bits from the USF field in different positions ineach burst.

The selecting module 1301 may be a processor 1304 of the controllingnode 140.

In some embodiments, the block may be configured to be backwardscompatible by the USF field being mapped over the four bursts so thatthe receiving device 102 lacking a specific configuration to support theblock format, may be enabled to decode the USF carried by the block.

The controlling node 140 may be further configured to, e.g., by means ofa sending module 1302 configured to, send, to the transmitting device101, the indication for the selected block format.

The sending module 1302 may be the processor 1304 of the controllingnode 140.

The controlling node 140 may be configured to perform other actions withother modules 1303 configured to perform these actions within thecontrolling node 140. Each of the other modules 1303 may be theprocessor 1304 of the controlling node 140, or an application running onsuch processor.

The embodiments herein may be implemented through one or moreprocessors, such as a processor 1304 in the controlling node 140depicted in FIG. 13, together with computer program code for performingthe functions and actions of the embodiments herein. The program codementioned above may also be provided as a computer program product, forinstance in the form of a data carrier carrying computer program codefor performing the embodiments herein when being loaded into the in thecontrolling node 140. One such carrier may be in the form of a CD ROMdisc. It is however feasible with other data carriers such as a memorystick. The computer program code may furthermore be provided as pureprogram code on a server and downloaded to the controlling node 140.

The controlling node 140 may further comprise a memory 1305 comprisingone or more memory units. The memory 1305 is arranged to be used tostore obtained information, store data, configurations, schedulings, andapplications etc. to perform the methods herein when being executed inthe controlling node 140.

In some embodiments, the controlling node 140 may receive informationthrough a receiving port 1306. In some embodiments, the receiving port1306 may be, for example, connected to two or more antennas incontrolling node 140. In other embodiments, the controlling node 140 mayreceive information from another structure in the wirelesscommunications network 100 through the receiving port 1306. Since thereceiving port 1306 may be in communication with the processor 1304, thereceiving port 1306 may then send the received information to theprocessor 1304. The receiving port 1306 may also be configured toreceive other information.

The processor 1304 in the controlling node 140 may be further configuredto transmit or send information to e.g., the transmitting device 101,through a sending port 1307, which may be in communication with theprocessor 1304 and the memory 1305.

Those skilled in the art will also appreciate that the selecting module1301, the sending module 1302, and the other modules 1303 describedabove may refer to a combination of analog and digital modules, and/orone or more processors configured with software and/or firmware, e.g.,stored in memory, that, when executed by the one or more processors suchas the processor 1304, perform as described above. One or more of theseprocessors, as well as the other digital hardware, may be included in asingle Application-Specific Integrated Circuit (ASIC), or severalprocessors and various digital hardware may be distributed among severalseparate components, whether individually packaged or assembled into aSystem-on-a-Chip (SoC).

Also, in some embodiments, the different modules 1301-1303 describedabove may be implemented as one or more applications running on one ormore processors such as the processor 1304.

Thus, the methods according to the embodiments described herein for thecontrolling node 140 may be implemented by means of a computer programproduct, comprising instructions, i.e., software code portions, which,when executed on at least one processor, cause the at least oneprocessor to carry out the actions described herein, as performed by thecontrolling node 140. The computer program product may be stored on acomputer-readable storage medium. The computer-readable storage medium,having stored thereon the computer program, may comprise instructionswhich, when executed on at least one processor, cause the at least oneprocessor to carry out the actions described herein, as performed bycontrolling node 140. In some embodiments, the computer-readable storagemedium may be a non-transitory computer-readable storage medium, such asa CD ROM disc, or a memory stick. In other embodiments, the computerprogram product may be stored on a carrier containing the computerprogram just described, wherein the carrier is one of an electronicsignal, optical signal, radio signal, or the computer-readable storagemedium, as described above.

When using the word “comprise” or “comprising” it shall be interpretedas non-limiting, i.e. meaning “consist at least of”.

The embodiments herein are not limited to the above described preferredembodiments. Various alternatives, modifications and equivalents may beused. Therefore, the above embodiments should not be taken as limitingthe scope of the invention. It is to be understood that the embodimentsare not to be limited to the specific examples disclosed, and thatmodifications and other variants are intended to be included within thescope of this disclosure. Although specific terms may be employedherein, they are used in a generic and descriptive sense only and notfor purposes of limitation.

EXAMPLES RELATED TO THE EMBODIMENTS DESCRIBED HEREIN

More specifically, the following are examples related to transmittingdevice related embodiments, receiving device related embodiments, andcontrolling node related embodiments.

The transmitting device embodiments relate to FIGS. 8 and 11.

A method performed by a transmitting device such as the transmittingdevice 101, e.g., the network node 110, for transmitting a block to areceiving device such as the receiving device 102, the transmittingdevice 101 and the receiving device 102 operating in a wirelesscommunications network 100, may comprise the following action:

-   -   Transmitting 802 a block, such as a radio block, to the        receiving device 102, the block comprising four bursts, such as        radio bursts, each of the four bursts further comprising Uplink        State Flag, USF, fields, Stealing Flag, SF, fields and data and        header fields, wherein the USF and the SF fields are interleaved        and mapped over the four bursts, wherein the data and header        fields are interleaved over one burst but repeated over the four        bursts, and wherein the data and header fields are overlapping        and overridden by bits from the USF field in different positions        in each burst. The transmitting device 101 may be configured to        perform this action 802, e.g. by means of the transmitting        module 1101 configured to perform this action, within the        transmitting device 101. The transmitting module 1101 may be a        processor 1104 of the transmitting device 101, or an application        running on such processor.

In some embodiments, the method may comprise the following action:

-   -   Receiving 801 from the controlling node 140 operating in the        wireless communications network 100, an indication for the block        for transmission to the receiving device 102, the block having        been selected by the controlling node 140, e.g., from a        plurality of block formats. The transmitting device 101 may be        configured to perform this action 801, e.g. by means of the        receiving module 1102 configured to perform this action, within        the transmitting device 101. The receiving module 1102 may be        the processor 1104 of the transmitting device 101, or an        application running on such processor. A format of the block may        correspond to the block comprising four bursts, each of the four        bursts further comprising Uplink State Flag, USF, fields,        Stealing Flag, SF, fields and data and header fields, wherein        the USF and the SF fields are interleaved and mapped over the        four bursts, wherein the data and header fields are interleaved        over one burst but repeated over the four bursts, and wherein        the data and header fields are overlapping and overridden by        bits from the USF field in different positions in each burst. In        action 801, the transmitting device 101 may therefore receive a        selected block format corresponding to the format just        described, for transmission to the receiving device 102. The        selected block format may have been selected from a plurality of        other formats, the other formats comprising for example, a        legacy block format, as described herein. The transmitting        device 101, in action 802 may then be understood to transmit the        block in the block format selected by the controlling node 140.        In other words, the block transmitted in action 802 corresponds        to the format described, as selected by the controlling node        140.

In some embodiments, the receiving 801 may further comprise anindication for the selected state for the USF field in the selectedblock.

The transmitting device 101 may be configured to perform other actionswith other modules 1103 configured to perform these actions within thetransmitting device 101. Each of the other modules 1103 may be theprocessor 1104 of the transmitting device 101, or an application runningon such processor.

In some embodiments, the transmitting device 101 may be a BTS and thereceiving device 102 may be a mobile station.

In some embodiments, the transmitting device 101 may be a mobile stationand the receiving device 102 may be a BTS.

In some embodiments, the controlling node 140 may be a BSC.

In some embodiments all the actions may be performed. In someembodiments, one or more actions may be performed. One or moreembodiments may be combined, where applicable. All possible combinationsare not described to simplify the description.

The transmitting device 101 may comprise an interface unit to facilitatecommunications between the transmitting device 101 and other nodes ordevices, e.g., the receiving device 102. The interface may, for example,include a transceiver configured to transmit and receive radio signalsover an air interface in accordance with a suitable standard.

The receiving device related embodiments relate to FIGS. 9 and 12.

A method performed by a receiving device such as the receiving device102, e.g., the wireless device 120, for receiving the transmitted blockfrom the transmitting device 101, the transmitting device 101 and thereceiving device 102 operating in the wireless communications network100, may comprise one or more of the following actions:

-   -   Receiving 901 the block from the transmitting device 101, the        block comprising four bursts, each of the four bursts further        comprising Uplink State Flag, USF, fields, Stealing Flag, SF,        fields, and data and header fields, wherein the USF and the SF        fields are interleaved and mapped over the four bursts, wherein        the data and header fields are interleaved over one burst but        repeated over the four bursts, and wherein the data and header        fields are overlapping and overridden by bits from the USF field        in different positions in each burst. The receiving device 102        may be configured to perform this action 901, e.g. by means of a        receiving module 1201 configured to perform this action, within        the receiving device 102. The receiving module 1201 may be a        processor 1204 of the receiving device 102, or an application        running on such processor. The data field may be referred to        herein as the data part of the block. The header field may be        referred to herein as the header part of the block;    -   Decoding 902 the block according to an indication comprised in        the SF field of the received block. The receiving device 102 may        be configured to perform this action 902, e.g. by means of a        decoding module 1202 configured to perform this action, within        the receiving device 102. The decoding module 1202 may be the        processor 1204 of the receiving device 102, or an application        running on such processor.

The receiving device 102 may be configured to perform other actions withother modules 1203 configured to perform these actions within thereceiving device 102. Each of the other modules 1203 may be theprocessor 1204 of the receiving device 102, or an application running onsuch processor.

In some embodiments all the actions may be performed. In someembodiments, one or more actions may be performed. One or moreembodiments may be combined, where applicable. All possible combinationsare not described to simplify the description.

The receiving device 102 may comprise an interface unit to facilitatecommunications between the receiving device 102 and other nodes ordevices, e.g., the transmitting device 101. The interface may, forexample, include a transceiver configured to transmit and receive radiosignals over an air interface in accordance with a suitable standard.

The controlling node related embodiments relate to FIGS. 10 and 13.

A method performed by a controlling node such as the controlling node140, e.g., a BSC, for selecting the block for transmission by atransmitting device 101 to a receiving device 102, the controlling node140, the transmitting device 101, and the receiving device 102 operatingin the wireless communications network 100, may comprise one or more ofthe following actions:

-   -   Selecting 1001 the block for transmission by the transmitting        device 101 to the receiving device 102, the block comprising        four bursts, each of the four bursts further comprising Uplink        State Flag, USF, fields, Stealing Flag, SF, fields, and data and        header fields, wherein the USF and the SF fields are interleaved        and mapped over the four bursts, wherein the data and header        fields are interleaved over one burst but repeated over the four        bursts, and wherein the data and header fields are overlapping        and overridden by bits from the USF field in different positions        in each burst, the block being selected, e.g., from a plurality        of block formats. The controlling node 140 may be configured to        perform this action 1001, e.g. by means of a selecting module        1301 configured to perform this action, within the controlling        node 140. The selecting module 1301 may be a processor 1304 of        the controlling node 140, or an application running on such        processor;    -   Sending 1003, to the transmitting device 101, an indication for        the selected block. The controlling node 140 may be configured        to perform this action 1003, e.g. by means of a sending module        1302 configured to perform this action, within the controlling        node 140. The sending module 1302 may be the processor 1304 of        the controlling node 140, or an application running on such        processor.

In some embodiments, the method may comprise the following action:

-   -   Selecting 1002 a state for the USF field in the selected block,        and wherein the sent indication comprises an indication for the        selected state for the USF field. The controlling node 140 may        be configured to perform this action 1002, e.g. by means of the        selecting module 1301 configured to perform this action, within        the controlling node 140.

The controlling node 140 may be configured to perform other actions withother modules 1303 configured to perform these actions within thecontrolling node 140. Each of the other modules 1303 may be theprocessor 1304 of the controlling node 140, or an application running onsuch processor.

In some embodiments all the actions may be performed. In someembodiments, one or more actions may be performed. One or moreembodiments may be combined, where applicable. All possible combinationsare not described to simplify the description.

The controlling node 140 may comprise an interface unit to facilitatecommunications between the controlling node 140 and other nodes ordevices, e.g., the transmitting device 101. The interface may, forexample, include a sender configured to send and receive signals over awired interface in accordance with a suitable standard.

What is claimed is:
 1. A method performed by a receiving deviceconfigured for operation in a communications network, the methodcomprising: receiving, from a transmitting device in the communicationsnetwork, four bursts comprising a block mapped according to a selectedblock format, wherein the block comprises a plurality of data and headerbits; determining whether the selected block format corresponds to afirst block format in which the plurality of data and header bits arerepeated in a corresponding plurality of same first positions in allfour bursts; and demodulating the plurality data and header bits basedon the determination of whether the selected block format corresponds tothe first block format.
 2. The method of claim 1, wherein: the blockfurther comprises a plurality of Stealing Flag (SF) bits; anddetermining whether the selected block format corresponds to the firstblock format is based on values of the SF bits.
 3. The method of claim1, wherein: the block further comprises a plurality of Uplink State Flag(USF) bits; and in the first block format, a different portion of theUSF bits overrides a corresponding different portion of the plurality ofdata and header bits in each of the four bursts.
 4. The method of claim1, wherein if it is determined that the selected block formatcorresponds to the first block format, demodulating the plurality ofdata and header bits comprises: estimating a frequency offset of thereceiving device, in relation to the transmitting device, based on theplurality of data and header bits received in at least one pair ofconsecutive bursts, of the four bursts; and determining a correctedplurality of data and header bits based on removing the estimatedfrequency offset from the plurality of data and header bits.
 5. Themethod of claim 4, wherein estimating the frequency offset comprisesdetermining a complex correlation between: the plurality of data andheader bits as received in a first burst of each pair of the at leastone pair of consecutive bursts; and the plurality of data and headerbits as received, at corresponding positions, in a second burst of eachpair of the at least one pair of consecutive bursts.
 6. The method ofclaim 4, wherein if it is determined that the selected block formatcorresponds to the first block format, demodulating the plurality ofdata and header bits further comprises: accumulating each particularbit, of the corrected plurality of data and header bits, from a sameposition in all four bursts, wherein the same position for theparticular bit is different than the respective same positions in allfour bursts for the other bits comprising the corrected plurality ofdata and header bits.
 7. The method of claim 6, wherein: the blockfurther comprises a plurality of Uplink State Flag (USF) bits; in thefirst block format, a different portion of the USF bits overrides acorresponding different portion of the plurality of data and header bitsin each of the four bursts; and accumulating each particular bit, of thecorrected plurality of data and header bits, from the same position inall four bursts comprises accumulating a corrected USF bit overridingthe particular bit in any of the four bursts.
 8. The method of claim 1,further comprising determining whether the selected block formatcorresponds to a second block format in which the each of the pluralityof data and header bits is transmitted in a position, within the fourbursts, that is different from the respective positions, within the fourbursts, in which other bits of the plurality of data and header bits aretransmitted.
 9. The method of claim 8, wherein the block furthercomprises a plurality of Uplink State Flag (USF) bits; in each of thefour bursts, a different portion of the USF bits overrides acorresponding different portion of the plurality of data and headerbits; and the corresponding different portions are the same for thefirst and second block formats.
 10. The method of claim 8, whereindemodulating the data and header bits is further based on thedetermination of whether the selected block format corresponds to thesecond block format.
 11. The method of claim 10, wherein if it isdetermined that that selected block format corresponds to the secondblock format and not the first block format, demodulating the pluralityof data and header bits comprises: determining a corrected plurality ofdata and header bits based on removing, from the plurality of data andheader bits, a particular frequency offset estimated prior to receivingthe four bursts comprising the block; and accumulating each particularbit, of the corrected plurality of data and header bits, from only theposition, within the four bursts, that is different from the respectivepositions of the other bits within the four bursts.
 12. A receivingdevice configured for operation in a communications network, thereceiving device comprising: a receiver configured to receive, from atransmitting device in the communications network, four burstscomprising a block mapped according to a selected block format, whereinthe block comprises a plurality of data and header bits; a processoroperatively associated with the receiver and configured to: determinewhether the selected block format corresponds to a first block format inwhich the plurality of data and header bits are repeated in acorresponding plurality of same first positions in all four bursts; anddemodulate the plurality data and header bits based on the determinationof whether the selected block format corresponds to the first blockformat.
 13. The receiving device of claim 12, wherein: the block furthercomprises a plurality of Stealing Flag (SF) bits; and the processor isconfigured to determine whether the selected block format corresponds tothe first block format based on values of the SF bits.
 14. The receivingdevice of claim 12, wherein: the block further comprises a plurality ofUplink State Flag (USF) bits; and in the first block format, a differentportion of the USF bits overrides a corresponding different portion ofthe plurality of data and header bits in each of the four bursts. 15.The receiving device of claim 12, wherein if is determined that theselected block format corresponds to the first block format, theprocessor is configured to demodulate the plurality of data and headerbits by: estimating a frequency offset of the receiving device, inrelation to the transmitting device, based on the plurality of data andheader bits received in at least one pair of consecutive bursts, of thefour bursts; and determining a corrected plurality of data and headerbits based on removing the estimated frequency offset from the pluralityof data and header bits.
 16. The receiving device of claim 15, whereinthe processor is configured to estimate the frequency offset bydetermining a complex correlation between: the plurality of data andheader bits as received in a first burst of each pair of the at leastone pair of consecutive bursts; and the plurality of data and headerbits as received, at corresponding positions, in a second burst of eachpair of the at least one pair of consecutive bursts.
 17. The receivingdevice of claim 15, wherein if it is determined that the selected blockformat corresponds to the first block format, the processor is furtherconfigured to demodulate the plurality of data and header bits by:accumulating each particular bit, of the corrected plurality of data andheader bits, from a same position in all four bursts, wherein the sameposition for the particular bit is different than the respective samepositions in all four bursts for the other bits comprising the correctedplurality of data and header bits.
 18. The receiving device of claim 17,wherein: the block further comprises a plurality of Uplink State Flag(USF) bits; in the first block format, a different portion of the USFbits overrides a corresponding different portion of the plurality ofdata and header bits in each of the four bursts; and the processor isconfigured to accumulate each particular bit, of the corrected pluralityof data and header bits, from the same position in all four bursts byaccumulating a corrected USF bit overriding the particular bit in any ofthe four bursts.
 19. The receiving device of claim 12, wherein theprocessor is further configured to determine whether the selected blockformat corresponds to a second block format in which the each of theplurality of data and header bits is transmitted in a position, withinthe four bursts, that is different from the respective positions, withinthe four bursts, in which other bits of the plurality of data and headerbits are transmitted.
 20. The receiving device of claim 19, wherein theblock further comprises a plurality of Uplink State Flag (USF) bits; ineach of the four bursts, a different portion of the USF bits overrides acorresponding different portion of the plurality of data and headerbits; and the corresponding different portions are the same for thefirst and second block formats.
 21. The receiving device of claim 20,wherein the processor is further configured to demodulate the data andheader bits based on the determination of whether the selected blockformat corresponds to the second block format.
 22. The receiving deviceof claim 21, wherein if it is determined that that selected block formatcorresponds to the second block format and not the first block format,the processor is configured to demodulate the plurality of data andheader bits by: determining a corrected plurality of data and headerbits based on removing, from the plurality of data and header bits, aparticular frequency offset estimated prior to receiving the four burstscomprising the block; and accumulating each particular bit, of thecorrected plurality of data and header bits, from only the position,within the four bursts, that is different from the respective positionsof the other bits within the four bursts.